I disagree. The first one is false. No exponent rules apply if the bases AND the exponents are different.
The second one is true. Bases are the sane so you add exponents. You get 3 to the -5 power. Written with positive exponents it’s 1/3 to the 5.
3r-6=-21
3r-6+6=-21+6 (Add 6 to both sides...)
3r=-15
r=-5
3r-6=21
3r-6+6=21+6 (Add 6 to both sides...)
3r=27
r=9
r=-5 or r=9
Answer:
2 is the answer I did this once in class
Answer:

Step-by-step explanation:
Given expression : 
Solving further :


So, 
So, The given expression is equivalent to Option A
So, Option A is the answer
Answer:
(a+6)²
by identity (a+b)²=a²+2ab+b²
(a+6)²= a²+ 2×a×6 + 6²
= a²+ 12a + 36
(2a)²+5a = 4a²+5a